ABSTRACT
ObjectiveTo study whether the abductor pollicis brevis been effected by the reinnervation of the Riche-Cannieu anastomosis in the median nerve injury cases.MethodsCollect 43 cases (29male,14 female,mean age 32.6)corresponds with the study needs: (1)The traumatic median nerve injury (proved by the results of electrophysiological examine and the clinic diagnose)on or below the forearm.(2)The existence of RCA was verified by the electrophysiological examine results,and the amplitude of electric potential was under 1mv.(3) Rule out the cases with the other injure of nerve or nervous system disease and cervical vertebra disease,diabetes patient.The analysis base on the results of 43 case's periodical examine,the periodical criteria as following: within 2-4th week,within the 2-4thmonth and 1 year after the injury.Results Forty-three cases had not obvious recovery indication of the median nerve under the clinical and electrophysiological aspect,eight cases of abductor pollicis brevis function improved quickly in 3 months,the relevant CMAP amplitude of Riche-Cannieu anastomosis increased apparently,the EMG (Electromyography)results of abductor pollicis brevis ameliorated accordingly.ConclusionIn the case of RCA combined with the median nerve injury,the abductor pollicis brevis fibra might be dominated by RCA reinnervation when losing domination of median nerve,the reinnervation process will much faster than the regeneration process of the broken nerve.
ABSTRACT
Objective To explore the optimal electrophysiologieal approach for detecting Riehe-Cannieu anastomosis(RCA),an anomalous anastomosis between the deep branch of ulnar nerve and the recurrent branch of the medial nerve in the palm of the hand,and to estimate its incidence. Methods One hundred subjects(56 male,44 female,mean age 37.8 years)without any hand motor or sensory dysfunction were selected randomly.The ulnar nerve was stimulated at both the elbow and wrist,and recordings were made from the abductor pollicis brevis,which is normally innervated by the medial nerve,to document any compound muscle action potentials(CMAP).CMAP recorded from both points during stimulation is an accepted indicator of RCA.Group A comprised 40 hands of 20 subjects,while group B included 160 hands of 80 subjects.Surface electrode stimulation was used in both groups.Surface and needle electrode recording was used in group A,while only needle electrode recording was used in group B.Results In group A,31 hands of 16 subjects were found to have RCA by means of surface electrode recording,but only 6 hands of 3 subjects were found to have RCA by means of concentric needle electrode recording.There was a difference of up t0 80.6% between results obtained by the 2 recording methods.In group B,35 hands of 20 subjects were found to have RCA.A total of 41 hands of 23 subjects among the 100 were found to have RCA when concentric needle electrode recording was used(20.5%incidence). Conclusion The type of recording electrode influences the accuracy of RCA examination.An accurate and reliable result can be obtained by using a concentric needle electrode.The abductor pollicis brevis can be anomalously innervated by the ulnar nerve because of RCA.When both the medial and ulnar nerve have been injured.RCA might result in anomalous clinical symptoms and electrophysiological findings.Thoroughly understanding this anomaly is of crucial importance in the clinical evaluation and diagnosis of medial or ulnar nerve injury,as well as to avoid mistakenly interpreting the electrophysiological data when Riche-Cannieu anastomosis is present.
ABSTRACT
Objective To study the effect of the Riche-Cannieu anastomosis, an anomalous anastomosis between the deep branch of ulnar nerve and the recurrent branch of median nerve in the palm of the hand, on the diagnosis of patients with carpal tunnel syndrome. Methods Twelve patients (2 male, 10 female, mean age 49.8 years) with carpal tunnel syndrome with the presence of Riche-Cannieu anastomosis were tested in this study. Their clinical data including the symptoms and signs, electrophysiological findings and diagnosis were collected and discussed in relation to an anatomical review of these nerves. Results Due to the existence of the Riche-Cannieu anastomosis, the patients with carpal tunnel syndrome spared part or all of the function of the abductor pollicis brevis (APB) muscle. It may result in an unconformity of the patients′lesion degree caused by carpal tunnel syndrome and its clinical symptoms and electrophysiological findings. Conclusion Knowledge of the Riche-Cannieu anastomosis is of crucial importance in the clinical evaluation, diagnosis and treatment of carpal tunnel syndrome, as well as in avoiding errors in interpreting the electrophysiological data of the patients.